__put_user_size() relies upon its first argument having the same type as what
the second one points to; the only other user makes sure of that and
unsafe_put_user() should do the same.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
 #define unsafe_put_user(x, ptr, err_label)                                     \
 do {                                                                           \
        int __pu_err;                                                           \
-       __put_user_size((x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT);         \
+       __put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT);             \
        if (unlikely(__pu_err)) goto err_label;                                 \
 } while (0)